Forming die



Nov. 14, 1961*` Filed oct. 19, 1959.

E. N. FABBRO ET AL FORMING DIE 4 Sheets-Sheet 1 IN VEN 701W` A Trae/var Nov. 14, 1961 E. N. FABBRO ETAL 3,008,508

FORMING DIE Filed Oct. 19, 1959 4 Sheets-Sheet 2 N f.' N N *60 H\ I m @n 2 f X ATTO'e/YEY Nov. 14, 1961 E. N. FABBRO ET AL 3,008,508

FORMING DIE Filed ot. 19, 1959 4 sheets-sheet s Nov. 14, 1961 E, N, FABBRO ET AL 3,008,508

FORMING DIE Filed Oct. 19, 1959 4 Sheets-Sheet 4 Uff V @D i i u yf i ATTORNEY Patented Nov. 14, 1961 3,068,508 FORMING DlE Emil Napoleon Fabbro, St. Clair Shores, Teddy D. Nowahowski, Rochester, and Harold G. Wilkin, Birmingham, Mich., assignors to General Motors Corporation, De-

troit, Mich., a corporation of Delaware Filed Get. 19, 1959, Ser. No. 847,145 11 Claims. (Cl. 153-46) This invention relates to material forming apparatus and more particularly to apparatus for controlling a forming die during a Work cycle.

The recent trend toward high styled` automobiles and appliances with complicated and extenuated surface areas having intricate bends has resulted .in a need for more accuracy and control of power application during a forming operation. in order to obtain a high finish on the materials used, the lforming operation must also be accomplish with `a minimum of surface marring. It has been our experience that previous forming apparatus h-ave often scratched or blemished a material surface during the forming operation due to slippagepbetween the surfaces of the forming material and the forming die, and because of inaccurate power application to the forming die.

The objects of this invention are to provide forming apparatus which eliminate slippage between a die and a sheet of material during a bending operation; 'to provide means to maintain a uniform optimum power application during a bending operation; to provide means to accommodate any die shape or 'angle of bend with a single basic forming apparatus; and to utilize a minimum number of parts facilitating assembly, maintenance and space requirements.

Other objects and advantages of this invention will be apparent from the following detailed description and the accompanying drawings in which:

FIG. 1 is a partitioned side view, partly inV section, of the control apparatus; A

FIG. 2 isa cross-sectional view` of the apparatus taken along line 2-2 in FIG. 1, showing the die in a closed position;

FIG. 3 is `an end view of the apparatus showing the die in an open position;

FiG. 4 is a partial sectional detail view taken along line 4 4 in FlG. l;

FIG. 5 is a partial sectional detail View taken along the line 5-5 in FIG. l; andy v FIG. 6 is a partial sectional View taken along the line 6--6 in FIG. 2.

Referring now to l, a die control member 10 in the form of an elongated rail is secured to a support member 12 by a pair of pivot arms 13 and 14. The pivot arms are pivotally connected to the support member 12 by pins 15 and 16 pivotally supported in bushings '.17 and 18 which depend from the support member 12 and are secured thereto by retaining plates 20, as Shown in FIG. 4. The

pins are supported by bearing members 22 in the bushings 17 and 1S.

Referring again to FIG. l, a bending die 24 is shown in phantom behind the die control rail 10 land is pivotally supported at its extremities by the trunnions 25 and 26. rIhe trunnions are spaced beyond the ends of the forming die 24 by support llanges. The lower edge 27 of the bending die is coaxially aligned with the folding Vbreak 0f the material to be formed and is further coaxially aligned with the pivotal axis of the die 24 as represented by the central axis 28 of the trunnions. The central axis of the rtunnions is therefore in line with and parallel to the 4lower edge 27 of the bending die 24.

Grooves 30 and 32 are provided in the .pivot arms 13 and 14 and retain control pins 34 and 36'. The control pins are supported by support members 38, 40, 42 and 44 that are rigidly connected to a power lever or link 46.

As illustrated in detail in FIG. 5, the support members 38, 40, 42 and 44 form a bifurcated support for each of the control pins. l'he pins are supported by bearing members 43, and the support members may be attached to the power lever by screw members 50. The grooves are of sufficient length to prevent a power transmitting engagement between the pins 34 and 36 and the pivot arms 13 and 14 during the forming operation as the die 24 is rotated from the open position of FIG. 3 to the closed position of FIG. 2. As shown in FIG. 2 the pins engage the rear end of the grooves at the completion of the work cycle.k

A plurality of power transferring drive blocks 52, 54, 56, 58 and 60 are detachably secured to the die control member 10. As shown in FIG. 3, the drive blocks may be secured by screw members 62 and ra portion 64 of each of the `drive blocks is included and contoured for engagement with a plurality of canrmembers 66, 68, 70, 72 and 74 detachably secured to the die control member l0 by the screw members 76. Referring to FlG. 3, the cam members are provided with a cam surface 78 that is contoured to maintain power transferring Contact between the drive blocks Iand the cam members at an optimum angle of inclination and surface contact in regard to the particular configuration of the bending die 24 throughout the rotational range of the die. The drive blocks and the contoured portion 64 thereof provide cam surface follower means. Since the cam members and drive blocks are detachable, different bending dies may readily be provided with a set of drive blocks and cam members designed to provide optimum results and with the particular die being usable without changing any of the other equipment.

Referring now to FIGS. 2 and y3, a hinge ,member 80 interconnects the control member 10 land the die member 24. The die control l-member 10l is'slidably connected to the hinge member 80 along a slide surface 82 thereof. As shown in FIG. 6, the slidable connection comprises an internal gib and key S4 secured within a slide guide 86. A plurality of these slidable connections are provided as needed. The hinge member S0 is pivotally connected to the die 24 by a pivot pin 96 supported by a ange 88. As many of these pivotal connections as are necessary to support the die mayv be provided. The pivot pin is pivotally connected to the die within a recess 92 designed to accommodate the flange throughout the range of rotation of the die. An assembly hole 93 is provided for the pin 90. FiGS. 2 and 3 illustrate that the hinge member is also provided with a slide surface 94 in sliding engagement with an adjacent surface 96 of the die. The surface 96 is contoured to maintain optimum engagement between the hinge and the die during the work cycle.

The surface 9'8 of the die is contoured to obtain the desired bend in `a sheet of material 102 which is to be bent about the axis 100. It is to be noted that the lower edge of the die 27 and the folding break of the material are parallel to and in line with one another to be substantially coaxial. Additional die members 104 and 106 are suitably positioned along the bending axis 100 to 0btain the desired contour in the material 162.

In. operation 'In operation, with thev die in the open position illustrated in FIG. 3, the sheet of material 102 is placed in the position indicated abut-ting the contoured facing 98 of the die member 24. As power is applied through the power lever 46 to close the die, the drive blocks 52, 54,v

lever 46, and as the die control member is rotated about the pivotal connections the cam surfaces on the cam members maintain contact between the drive blocks and the cam members at an optimum angle in relation to the axis of bend lo@ of the sheet of material. In addition, as the die control member is rotated, the slidable connection between the control member 10 and the hinge plate Sti permits an intermediate power transfer that eliminates any slippage between the die and the sheet of material. Thus, the hinge member slides outwardly away from the pivotal axis of the control member 10 and pivots in relation to the die 24 as it is closed. The power 4transfer between the hinge member and the die is accomplished through the cam surface 96 which rides on the surface 94 of the hinge member land therefore eliminates undue strain on the pivotal connection 90. The pivotal connection 36 between the power lever 46 and the pivot arms i3 and lli serves no power transmitting function during the closing of the die because the grooves 3@ and 32 provide an unrestricted path throughout the entire bending operation. However, it should be noted that when the die is closed, as in IFIG. 2, the pins l34 `and 36 are in engagement with the inner rear surface of the grooves and provide a power return connection for Vthe apparatus on the return stroke of the power lever 46.

`It is apparent that as the die 24 rotates about its edge 27 there will be no slippage between the sheet material 102 and the contoured surface 9S of the die, because the die rotates about its lower line of contact wit-h the sheet of material and the folding break of the sheet. Thus, a uniform application of force is maintained and the finish on the sheet material is not marred in any way. When it is desired to change the die 24- to obtain different configurations, the hinge member '80 and the die 24 are disconnected as by removing the pin 99 through the assembly hole 93. A new die may then be mounted on the hinge member Si) and the drive blocks and cam members can be easily replaced by a new set adapted for -the new die. The main components of the apparatus require no changes or disassembly whatsoever.

Itshould be apparent that the details of construction of this invention may be subject to modifications without exceeding the scope of the appended cl-aims.

What we claim is:

1. Sheet material forming apparatus comprising a power source and a forming die movable about an axis of rotation between an open position and a forming position, a hinge member having a pivotal connection with said die, a slide surface on said hinge member opposite said pivotal connection, a die control member having a slide surface positioned in sliding engagement with said slide surface on said hinge member, said control member being pivoted for rotary movement about an axis parallel to the axis of rotation of said forming die, and a power transmitting link operatively connecting said power source and said die control member whereby said forming die may be rotated about said axis of rotation between said open position and said forming position.

2. Sheet material forming apparatus comprising a power source and a forming die movable about an axis of rotation between an open position and a forming position, a hinge member having a pivotal connection with said die, a slide surface on said hinge member opposite said pivotal connection, a die control member having a slide surface positioned in sliding engagement with said slide surface of said hinge member, said control member being pivoted for rotary movement about an axis parallel to the axis of rotation of said forming die, a cam surface provided on said die control member, said cam surface being contoured to maintain the application of force from said power source to said forming die at an optimum angle of inclination during rotation of said forming die, and a power link operatively conneeting'said power source and said die control member, cam surface follower means provided on said power link and adapted to slidingly engage said cam surface on said die control member whereby said forming die may be rotated about said axis of rotation between said open position and said forming position.

3. Sheet material forming apparatus comprising a power source and a forming die movable about an axis of rotation between an open position and a forming position, a hinge member having a pivotal connection with said die, a slide surface on said hinge member opposite said pivotal connection, a die control member having a slide surface positioned in sliding engagement with said slide surface of said hinge member, said control member being pivoted for rotary movement about an axis parallel to the axis of rotation of said forming die, a power transmitting link operatively connecting said power source and said die control member whereby said forming die may be rota-ted about said axis of rotation between said open position and said forming position, -a cam slot provided on said die control member, a pin carried by said power transmitting link and retained in said slot, said cam slot having a radial length greater than the length of radial movement of said forming die and positioned relative to said pin lto maintain the ends of said slot in space relation relative to said pin as saidr forming die is rotated from said open position to said forming position to prevent power transmission therethrough, and one of said ends of said slot being operatively associated with said pin at the completion of movement of said forming die from said open position to said forming position and being engaged with said one of said ends of said slot during movement of said forming die from said forming position to said open position to provide a power return for said forming die.

4. Sheet material forming apparatus comprising a power source and a forming die movable about an axis of rotation between an open position and a forming position, a hinge member having a pivotal connection with said die, a slide surface on said vhinge member opposite said pivotal connection, a `die control member having a slide surface positioned closely adjacent said slide surface of said hinge member, means slidably connecting saiddie control member and said hinge member and mechanically linking the slide surface of said hinge member and the slide surface of said die control member in substantially parallel alignment, said die control member being pivoted for rotary movement about an axis parallel to the axis of rotation of said forming die, and a power transmitting lever operatively connecting said power source and said die control member whereby said forming die may be rotated about said axis of rotation between said open position and said `forming position.

5. Sheet material forming apparatus comprising a power source and a forming die movable about an axis of rotation between an open position and a forming position, a hinge member having a pivotal connection with said die, a slide surface on said hinge member opposite said pivotal connection, a die control member having a slide surface positioned in sliding engagement with said slide surface of said hinge member, said die control member being pivoted for rotary movement about an axis parallel to the axis of rotation of said forming die, a power transmitting link operatively connecting said power source and said die control member whereby said forming die may be rotated about said axis of rotation between said open position and said forming position, a cam surface provided on said die control member, said cam surface being contoured to maintain a power transmitting engagement between said power link and said die control member as said die is rotated, and cam surface follower means provided on said power link and adapted to slidingly engage said cam surface on said die control member.

6. Sheet material forming apparatus comprising a power source and a formingdie movableabout an axis o f rotation between an open position and a forming position, a die control member operatively associated with said forming die, said control member being pivoted for rotary movement about an axis parallel to the axis of rotation of said forming die, a power transmitting link operatively connecting said power source and said die control member, a cam member detachably supported by said die control member and having a surface contoured to maintain a power transmitting engagement between said power link and said die control member, and a drive member detachably secured to said power link and having a surface contoured for engagement with said cam surface on said cam member whereby said forming die may be rotated about said axis of rotation between said open position and said forming position.

7. Sheet material forming apparatus comprising a power source and a forming die movable about an axis of rotation between an open position and a formingY position, a die control member operatively associated with said die, said control member being pivoted for rotary movement about an axis parallel to the axis of rotation of said forming die, a forming edge of said forming die being substantially coaxially aligned with said axis of rotation of said forming die, pivotal support members connected to said die, said support members being located beyond the ,side surfaces of said die and having central axes coaxial with said edge of said die, and a power transmitting link operatively connecting said power source and said die control member whereby said forming die may be rotated about said axis of rotation between said open position and said formingposition.

8. Material forming apparatus comprising a power source and a forming die movable about an 'axis of rotation between an open position and a forming position, a hinge member having a pivotal connection with said die, a slide surface on said hinge member, a die control member having a slide surface positioned adjacent the slide surface on said hinge member, means slidably connectingV said die control member and said hinge member and mechanically linking the slide surfaces of said members in substantially parallel alignment, Said die control member being pivoted for rotary movement about an axis parallel to the axis of rotation of said forming die, an edge of said forming die being substantially coaxially aligned with said axis of rotation of said forming die, pivotal support members connected to said die, said support members being axially spaced beyond the side surfaces of said die and having central axes coaxial with said edge of said die, and a power transmitting link operatively connecting said power source and said die control member whereby said forming die may be rotated aboutsaid axis of rotation between said open position and said forming position.

9. The apparatus as dened in claim 8 and having a cam surface provided on said die control member, said cam surface being contoured to maintain power transmitting engagement between said power link and said die control member at an optimum angle of inclination during rotation of said forming die. v

10. Sheet material 'forming apparatus comprising a power source and a forming die movable about an axis of rotation between an open position and a forming position, a die control member operativelyassociate'd with said forming die, said die control member being pivoted for rotary movement about an axis parallel to the-axis of rotation of said forming die, a cam member detachably supported by said die control member, a power transmitting link, a drive member detachably secured yto said power link, said cam member and said drive member having contoured surfaces adapted to maintain a power transmitting engagement between said power link and said die control member, an edge of said forming die being substantially coaxially aligned with said axis of rotation of said forming die and coaxial therewith, pivotal support members connected to said die, and said support members being axially spaced beyond the side surfaces of said die and having central axes coaxial with saidedge of said die whereby said forming die may be rotated about said axis of rotation between said open position and said forming position.

11. Sheet material forming apparatus comprising a power source and a forming die movable about an axis of rotation between an open position and a forming position, a hinge member having a pivotal connection with Y said die, a slide surface on said hinge member, a die control member having a slide surface positioned closely adjacent said slide surface of said hinge member, means slidably connecting said die control member and said hinge member and linking the slide surface of said hinge member and the slide surface of said die control member insubstantially parallel alignment, said control member being pivoted for rotary movement about an axis parallel to the axis of rotation of said forming die, a power transmitting link operatively connecting said power source and said die control member, a drive member detachably secured to said power link, a cam member detachably supported by said die control member and having a surface contoured to maintain a power transmitting engagement between said power link and said die control member, an edge of said forming die being substantially coaxially aligned with said axis of rotation of said forming die and coaxial therewith, pivotal support members connected to said die, and said support members being axially spaced beyond the side surfaces of said die and having central axes coaxial with said edge of said die whereby said forming die may be rotated about said axis of rotation between said open position and said forming position.

References Cited in the iile of this patent UNITED STATES PATENTS 2,568,691 Wildman Sept. 19, 1951 2,596,848 Green May 13, 1952 2,915,106 i Green Dec. 1, 1959 FOREIGN PATENTSy 711,502 Great Britain July 7, 1954 

